Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

$re = '/( \(\d{4}_\d{2}_\d{2} \d{2}_\d{2}_\d{2} \w{3}\))+|\1.\w{3}\n/'; $str = ' Acacia tree 2 (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg Acacia tree 2 (2015_12_03 14_18_17 UTC).jpg JOURNEY TO ARABIA (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png Acacia Tree 4 (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\AFRICA THE MOTHER OF US ALL 3 (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\AFRICAN MAN + CROCODILE (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\AFRICAN MAN + CROCODILE (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\AFRICAN MAN + CROCODILE (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\African muslim with favorite slave (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\African muslim with favorite slave (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\African muslim with favorite slave (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amagufwa ya bene Rwanda (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amagufwa ya bene Rwanda (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amagufwa ya bene Rwanda (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ama-Rank y\' inyenzi (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ama-Rank y\' inyenzi (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ama-Rank y\' inyenzi (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (1) (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (1) (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (1) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Amenhotep_III (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amenhotep3_head_03 (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amenhotep3_head_03 (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\amenhotep3_head_03 (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman] (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman] (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman] (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman]2 (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman]2 (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\an Egyptian [Sudanese woman]2 (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient Africa How Europeans have it wrong - Kevin MacDonald (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient Africa How Europeans have it wrong - Kevin MacDonald (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient Africa How Europeans have it wrong - Kevin MacDonald (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African script (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African script (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African script (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient African Scripts (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient African Scripts (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Ancient African Scripts (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African writings (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African writings (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ancient African writings (2015_12_03 14_18_17 UTC).png D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\ANCIENT HEBREWS DWELLINGS (2014_10_06 13_06_05 UTC) D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Bamwe mu basigajwe inyuma n’amateka bo mu Mudugudu wa Bukamba - LEVITES (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Baobab (Adansonia digitata) and elephant, Tanzania (2014_10_06 13_06_05 UTC) (2015_12_03 14_18_17 UTC).jpg D:\\Kmna\\Desktop\\FACE-PICTS\\RAW MATERIALS\\Baobab (Adansonia digitata) and elephant, Tanzania (2014_10_15 02_10_34 UTC) (2015_12_03 14_18_17 UTC).jpg'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php